Biofabrication of silver nanoparticles using leaf extract of Rhynchosia beddomei Baker: spectral characterization and their biological activities

S. Soneya, K. V. Saritha
2020 SN Applied Sciences  
The present study successfully investigated the biofabrication, spectral characterization, and biological activities of silver nanoparticles (AgNPs) using leaf aqueous extract of Rhynchosia beddomei Baker, important crop wild relatives of beans family (Phaseolus). Biofabrication of RB-AgNPs (R. beddomei leaf synthesized AgNPs) was confirmed by color change of the reaction solution from light yellow to dark brown. UV-Vis absorption spectrum of colloidal solution of RB-AgNPs showed characteristic
more » ... surface plasmon resonance peak at 431 nm. XRD pattern showed that biofabricated RB-AgNPs were crystalline in nature with FCC lattice and the crystallite size was found to be 9.36 nm. TEM micrographs showed that the biofabricated RB-AgNPs were mainly spherical in shape with 20-80 nm in size. DLS analysis revealed that average hydrodynamic radius of RB-AgNPs was 46.5 ± 8.5 nm. Further RB-AgNPs showed very good stability with zeta potential value of − 27.6 mV and polydispersity index of 0.203. FTIR analysis revealed that flavonoids and proteins take part in the bioreduction and stabilization of RB-AgNPs respectively. Biofabricated RB-AgNPs showed effective antioxidant activity against DPPH (IC 50 = 69.45 µg/mL) and H 2 O 2 (IC 50 = 87.43 µg/mL). RB-AgNPs showed significant antimicrobial activity against both Gram-positive and Gram-negative bacteria. RB-AgNPs were further proved to possess potent cytotoxic activity against different carcinomas including human cell lines of colon carcinoma (COLO205), prostate carcinoma (PC3) and breast cancer (MCF7). Thus RB-AgNPs showed multiple biological functions (3-in-1 system) including antioxidant, antimicrobial and anticancer activities. Graphic abstract Keywords Rhynchosia beddomei Baker · Silver nanoparticles · Biofabrication · TEM · DLS · COLO205 mutagenic and cytotoxicities due to exposure to different toxic irradiations and chemicals [19] . Hence there is a need to develop the green procedures to synthesize clean, non-toxic and biocompatible AgNPs. Different scientists around the globe developed simple and cost effective methods for the synthesis of AgNPs using different biological entities like bacteria, fungi, yeast and plants. Biofabricated AgNPs are clean, nontoxic and biocompatible. Biofabrication of AgNPs using yeast, bacteria and fungi involve tedious culturing methods and laborious procedures, and also time taking. Biofabrication of AgNPs using plants and their extracts involves simple steps, little duration, low-cost and ecofriendly approaches. Different plants including Mimusops elengi [20], Cassia fistula [21], Helicteres isora [22], Panax ginseng [23], Andrographis paniculata [24], Indigofera barberi [25], Clerodendrum phlomidis [26], Rubus glaucus [27], Olax scandens [28], Spondias dulcis [29] and Mussaenda erythrophylla [30] have been reported for the synthesis of AgNPs with different biological activities. Phytosynthesized AgNPs were proved to possess different applications. Malaria and arbovirus vectors have been successfully controlled using Mimusops elengi [20] . Phytosynthesized AgNPs have been reported to possess Biotechnology, Sri Venkateswara University, Tirupati, Chittoor district, Andhra Pradesh, India for providing lab facilities for biofabrication of silver nanoparticles (RB-AgNPs), antioxidant activity, and antimicrobial activity. The authors are grateful to DST-PURSE Centre, Sri Venkateswara University, for DLS analysis. The authors are also thankful to VIT-University, Vellore, Chennai, Tamil Nadu state, India for TEM analysis. The authors are also thankful to IICT-Hyderabad, Telangana state, India for anticancer activity and for technical assistance support extended during this work.
doi:10.1007/s42452-020-2717-0 fatcat:qywitk6lhzakjasmey7m5qtimq